Additional clockports for the A1200 ?

[Doobrey]

AFAIK, the Z-IV busboard uses the same offsets for it`s clockports too.
 It`s a simple 1 chip job to generate these new chip selct signals, although you can`t build it on stripboard cos the clockport headers are 2mm pitch instead of 0.1". So you`ll have to either get your own PCB made, or hack it into a 2mm IDC cable!

[Doobrey]

@ Stedy..
 That`s freaky, almost spot on the same as the one I did a few months back.
 The only thing different on mine is that I used the other half of the 139 and the spare_cs as its enable, to drive the spare_cs lines on the 4 ports, just for completeness.

 I suppose it`d be just as easy to decode the Net_cs for one of the ports, AFAIK Gayle uses less wait states on accesses to that memory space..

[Doobrey]

Deliberate mistake my ####  :lol:

 Wouldn`t the RTC on accelerator cards just take up the memory of the first port ?
 As for the Net_CS, I did have a few ideas..but getting hold of old ISA based ethernet chips with freely available docs is hard, although there is a company in the US that have a dev board that`ll just need an inverter on the interrupt line, and it`ll wire in fine.

 I will publish my stuff when I`ve finally tested it and got all the software working OK, which reminds me..
@Chris,
 Had any luck with the latest build I sent?

[Doobrey]

I was looking for the CS8900 or the RTL8019 (I think it`s the 8019!..can`t remember without digging out the schematics),
 Just can`t find them in the UK in small quantities, Maplins used to do it, but they`ve cut right back on their semiconductor range. Couldn`t find them at Farnell or RS either.
 I might have to resort to buying an ISA card and getting out the blowtorch :flame:

 How`s your 24bit IO card coming along? Have you scrapped the clockport version to concentrate on the parralel port verion?

[Doobrey]

You mean you have the rightmost 22pins on P9B ?
That is the clockport, all other pins were left over from the days when CBM were gonna make the A1200 with 1MB RAM, and sell an extra 1MB module that plugged into the P9A&B connectors.
 When they decided to make the A1200 a 2Mb machine, they simply didn`t bother soldering the pins to the unused holes to save money.
BTW, I`ve heard that some A1200s were built wrong, and had the 22pins meant for the clockport soldered to the leftmost side of the connector, if your A1200 is like that, dont plug anything into it, you could let out the magic blue smoke.

[Doobrey]

Hi Oli..
 Have you seen this ??

More details from their site www.embeddedether.net

Looks like it only needs Reset,AEN,and INTR inverted ..er and the small matter of a driver.At $49, it`s gonna be cheaper than getting my own PCB and the time spent burning my fingers.
 BTW, I seem to remember Jens Schoenfeld saying something about the interrupt line on the CS8900 not working when 8 bit mode, so the driver would have to do polling :-(

Also, www.edtp.com do a nice line in embedded network stuff, both kits and assembled.

[Doobrey]

Dunno if anyone is actually interested in a clockport network card,
 But there`s also this..

Apart from the layout, it looks pretty much the same as the one above except it costs $70..from www.embeddedethernet.com
Again..roll yer own drivers..

[Doobrey]

Methanoid wrote:
think of all those poor people who dont want t0o have PCMCIA cards hanging out their machines or buy Powers £20 rightangle adaptors for tower use!!!

Even with a right angle adapter, I had problems with my network card. The dongle cable was so stiff, it couldn`t bend out the way of the case without creating a bad connection on the network card!
 I ended up removing the PCMCIA port, and soldering a short length of SCSI ribbon (68w IDC, just right!)between the motherboard and the now loose PCMCIA socket. :-o
 That way, I could move the network card to the bottom of the case and not have to worry about jiggling the dongle to get a connection!

[Doobrey]

Not yet..fingers crossed,very soon though.
 I`ve got a couple of things ready to go to the PCB makers, and the software`s almost done for one of them.
 Just waiting until I`ve finalised the design of another project, then I`ll be getting all the PCBs made at once to save some of money.

[Doobrey]

Nothing that special Meth,
 The MP3 player is almost there, the chips finally arrived the other week after a world shortage, doing the stripboard version at the moment.
 The flashrom gizmo is just waiting for me to get the software finished, got a stripboard version that`s ugly as hell, but seems functional.
 Apart from that, everything else is nothing more than untested schematics or ideas.. RDS radio module for the mp3 player, probably with a controllable mixer too, Colour LCD display for the player, network card, serial card with one rs232 port, and one irda port..

But with work, life etc ,things get done when I have the time and enthusiasm (and money!) for them.

[Doobrey]

@JJ, Don`t wanna burst your bubble, but did you read on a few posts after that ??

@Meth, don`t worry..the FlashRom design has a built in splitter.
 BTW, I hope it hasn`t got anyones hopes up, but I won`t be selling anything. I`ll post the PCB designs and any needed software on my site when it`s ready. If a muppet like me can solder, I`m sure others can too :-)
 I was also thinking along the lines of an extended clockport..having a 16bit datapath and maybe an extra address line or two.  
 No use for existing cards, but could be handy for other people designing stuff.
 Any hardware hacker types got any ideas/thoughts about it?

[Doobrey]

GAH.. typed this out,just about to hit submit and ####ing BSOD  :pissed:

_BEER tells the CPU that a bus error happened during the current cycle, and depending on _HALT, the CPU either retries or generates an exception.

Anyway, put yer handbag away Stedy..

For what I have in mind, tapping direct into the bus is overkill, sure for a decent network card it`d be the best option though.

As for the rom signals..where do you think my flashrom fits?
Unfortunatley,it blocks access to the clockport (actually the stripboard version blocks most of East Anglia :-o), so I figures that since I was gonna extend the signals to a header on my board, I might as well split it.